Lenox ML180UHE installation instructions Thermostat Designations

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Before connecting the thermostat, check to make sure the wires will be long enough for servicing at a later date. Make sure that thermostat wire is long enough to facilitate future removal of blower for service.

Complete the wiring connections to the equipment. Use the provided unit wiring diagram and the field wiring diagram shown in figure 33. Use 18−gauge wire or larger that is suit- able for Class II rating for thermostat connections.

Electrically ground the unit according to local codes or, in the absence of local codes, according to the current Na- tional Electric Code (ANSI/NFPA No. 70). A green ground wire is provided in the field make−up box.

NOTE − The ML180UHE furnace contains electronic components that are polarity sensitive. Make sure that the furnace is wired correctly and is properly grounded.

Accessory Terminals

One line voltage ade terminal is provided on

the furnace integrated control. See figure 34 for integrated control configuration. This terminal is energized when the indoor blower is operating. Any accessory rated up to one amp can be connected to this terminal with the neutral leg of the circuit being connected to one of the provided neutral terminals. If an accessory rated at greater than one amp is connected to this terminal, it is necessary to use an exter-

Generator Use − Voltage Requirements

The following requirements must be kept in mind when specifying a generator for use with this equipment:

SThe furnace requires 120 volts + 10% (Range: 108 volts to 132 volts).

SThe furnace operates at 60 Hz + 5% (Range: 57 Hz to 63 Hz).

SThe furnace integrated control requires both polarity and proper ground. Both polarity and proper grounding should be checked before attempting to operate the furnace on either permanent or temporary power.

SGenerator should have a wave form distortion of less than 5% total harmonic distortion.

Thermostat

Install the room thermostat according to the instructions provided with the thermostat. See figure 31 for thermostat

designations. If the furnace is being matched with a heat pump, refer to the FM21 installation instruction or appropri-

ate dual fuel thermostat instructions.

ML180UHE and CONDENSING UNIT

THERMOSTAT DESIGNATIONS

(Refer to specific thermostat and outdoor unit.)

Thermostat

Furnace

Condensing

 

 

Unit

nal relay.

One line voltage ade terminal is provided on

the furnace integrated control. See figure 34 for integrated control configuration. This terminal is energized in the heating mode when the combustion air inducer is operat- ing. Any humidifier rated up to one amp can be connected to this terminal with the neutral leg of the circuit being con-

R

W1

Y

G

C

POWER

HEAT

COOLING

INDOOR BLOWER

COMMON

R

W

Y

G

C

*CONDENSING

UNIT

CONDENSING

UNIT

CONDENSING UNIT COMMON

nected to one of the provided neutral terminals. If a humidi- fier rated at greater than one amp is connected to this termi- nal, it is necessary to use an external relay relay.

One 24V "H" 1/4" spade terminal is provided on the furnace integrated control. See figure 34 for integrated control con- figuration. The terminal is energized in the heating mode when the combustion air inducer is operating and the pres- sure switch is closed. Any humidifier rated up to 0.5 amp can be connected to this terminal with the ground leg of the circuit connected to ground or the "C" terminal.

*NOTE −

FIGURE 31

Indoor Blower Speeds

1 − When the thermostat is set to AN ON," the indoor blower will run continuously on the fan speed when there is no cooling or heating demand.

2 − When the ML180UHE is running in the heating mode, the indoor blower will run on the heating speed.

3 − When there is a cooling demand, the indoor blower will run on the cooling speed.

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Contents Installation Instructions ML180UHE Table of ContentsUnit Dimensions − inches mm TOP ViewBurner Box Parts ArrangementMake−Up Box Heat Exchanger Combustion Air Inducer Gas ValveShipping and Packing List Safety InformationML180UHE Gas Furnace Use of Furnace as Construction Heater GeneralCombustion, Dilution & Ventilation Air Equipment in Confined Space ALL AIR from Inside Equipment in Confined Space Setting Equipment Return Air End Bottom Horizontal Application Installation Clearances Top LeftRight Typical Horizontal ApplicationFilters Duct SystemTop Vent Discharge VentingUpflow Position Left Side Vent DischargeSide Vent Discharge Horizontal Left Position Horizontal Right PositionHorizontal Left Position Side Vent Discharge − no modifications necessaryVent Connection Upflow and Horizontal Position Common Venting Using Metal−Lined Masonry Chimney −1/2 Cated or common venting system, you must inspect 18 − The common vent diameter must always be at least asFeet FAN + FAN FAN + NAT 130 Carbon Monoxide Poisoning Hazard Gas Piping Ers or straps. Install a drip leg in vertical pipe runs to− In some localities, codes may require the installation Gas supply piping should not allow more than 0.5W.C. dropRight−Side Air Discharge Horizontal ApplicationLeft−Side Air Discharge Electrostatic Discharge ESD Interior MAKE−UP BOX InstallationElectrical Thermostat Designations ML180UHE Schematic Wiring Diagram and Sequence of Operation Typical ML180UHE Field Wiring Diagram Integrated ControlFor Your Safety Read Before Lighting Unit Start−UpProper Combustion Gas Pressure AdjustmentGAS Meter Clocking Chart High AltitudeOther Unit Adjustments Manifold Pressure Settings at all AltitudesHeat FAN-OFF Time in Seconds No Jumper975 115 945 1380995 1345640 1940 420 1750 310 Single Side Return Air − Air volumes in bold require fieldOrder to maintain proper air velocity 230Service Electrical SHOCK, Fire Or Explosion Hazard−090, −110 −135 units ML180UHE BURNER, Combustion AIR Inducer AssemblyHeat Exchanger Removal −045 and −070 unitsPlanned Service Repair Parts ListIntegrated Control Diagnostic Codes RED LEDNormal Heating Mode Abnormal Heating Mode Heating Sequence of OperationHeating Sequence Normal Cooling Mode Abnormal Cooling Mode Cooling Sequence of OperationContinuous FAN Sequence of Operation Start−Up & Performance Check List Unit Operation Cooling ModeTemperature Rise Drain Line

Lennox Merit Series Gas Furnace Upflow/Horizontal air discharge, ML180UHE specifications

The Lenox ML180UHE is a reliable and efficient gas furnace that falls within the Lennox Merit Series. This model is designed for upflow or horizontal air discharge, making it versatile for various installation requirements. With its robust construction and advanced technology, the ML180UHE is ideal for homeowners seeking a dependable heating solution that combines comfort and efficiency.

One of the main features of the ML180UHE is its impressive 80% Annual Fuel Utilization Efficiency (AFUE) rating. This efficiency means that 80 cents of every dollar spent on fuel is used to heat your home while minimizing waste. This furnace is equipped with a multi-speed blower motor that enhances the overall air circulation in your home, providing consistent temperatures and improved comfort.

The ML180UHE features a durable heat exchanger made of high-quality materials, which ensures longevity and reliable performance. The design of the heat exchanger maximizes heat transfer efficiency, allowing the furnace to quickly warm your home while also maintaining optimal efficiency levels throughout its lifespan.

Lennox has integrated advanced technologies into the ML180UHE to enhance its operation and user experience. The unit is compatible with a variety of thermostats, including Lennox's innovative iComfort S30 Smart Thermostat, allowing for easy temperature control and programming capabilities. This smart technology can learn your preferences, optimize energy usage, and enable remote access through a smartphone app.

In addition to its energy efficiency, the ML180UHE offers quiet operation, making it an excellent choice for residential environments. The well-insulated cabinet helps to reduce noise levels, providing a peaceful indoor atmosphere.

Installation and maintenance are simplified with the ML180UHE due to its compact design and accessible components. The furnace is designed to fit into tight spaces, allowing for flexible installation options. Regular maintenance is uncomplicated, ensuring that homeowners can keep the unit running at peak performance with minimal effort.

Overall, the Lennox ML180UHE gas furnace provides users with a reliable, efficient, and quiet heating solution. With its combination of advanced technology, durable design, and ease of use, it is an excellent choice for anyone looking to enhance the comfort of their home while optimizing energy consumption.
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